Typewriter ribbon



April 2o, 1926. 1,581,510

C. CAMPBELL TYPEWRITE'R RIBBON Filed Dec. 16 1924 SPONGE PouNDED ToPLANT FIBERSQFORMEDINTO l 1 NKED MATERIAL fmmfonnmurfn ADMnxEQ THINSHEET INVENTOR CHARL E5 OIM/BELL @lia MM.

ATTORNEY Patented Apr. v2f), 1926i.

UNITED STATES 1,581,510 PATENT OFFICE.

CHARLES CAMPBELL, or NEW YoBx, N. Y.

'rYPEwBITEB BIBBoN.

Application led December 16, 1924. Serial No. 756,363.-

The present invention relates to typewriter ribbons and mo-reparticularly to improvements in typewriter ribbons made from matted orfelted plant fibres.

In my Patent No. 1,533,382 of April 14,

1925, I have described a typewriter ribbon made particularly from libresycomprising mainly the libres of the Japanese mulberry or Broussonetz'a'papy/referat, the invention being based on the discovery that thesefibres when felted and incorporated into the typewriter ribbon materialimpart the necessary tensile strength, enabling the ribbon to stand thewear and tear during use, and also has the quality of resistance torupture through which it withstands the pounding of the typewriter keyswithout disintegrating.

' As a| result of extended experimentation with mixtures of fibres Ihave discovered that while fibres other than Broussonetia libres may beadmixed therewith in the making of typewriter ribbons, thenecessarystrength and resistance to pounding,

being contributed mainly by the Broussonetia fibres, the addition ofcertain fibres in the mixture, such as hemp and jute, causes a seriousinterfrence with thek feedin qualities or ink dispersion through theriti.

I transferred from the ribbon to a paper by the impact pf the typewritertype on the` ribbon, the ink from otheradjacent parts of the ribboncreeps along the fibres thereof toward the area from which the ink hasbeen removed, the `flow taking place probably .through what we wouldterm capillary action whichkis a variable dependent on the amount ofspace between the fibres, sur

face tension and viscosity of the inking material, and various otherfactors. v It seems apparent that the inking material flows mainlythrough the various interstices between the libres and along thesurfaces thereof, and not through the libres themselves or lby soakingtransversely through the fibres. The amount of inking material employedin the ribbon must, of course, be limited in order to avoid the fillingof the type with ink, or producing what is generally termed blotting Itis therefore yapparent that the amount of ink used mustv be between thelimits where blotting would occur and a certain minimum amountcorresponding to what \is generally termed ribbon exhaustion, at whichpoint the amount of ink transferred to the paper is insullicient toproduce a legible impression, and that the larger the amount of inkwhich the ribbon will hold without blotting the Lbetter the ribbon. 1

Aside from the above considerations, the

ribbon must, when used, have a rapid rate lao paper Ain the usual way.There must be, in y other words, a radual redistribution of the ink onthe rib on, after a part thereof is removed.

In the making of typewriter ribbons from ,matted or felted plant fibres,particularly the Brozsonetz'a papyrz'fera, which'imparts the desiredstrength when admixed with other fibres, I 4have found that certainkinds i offibres interfere-,seriously with the feed qualities of theribbon. example, that fibres having a gummy surface or water-sheddingsurface interfere with the feeding qualities of a ribbon, and alsodecrease the ink holding or absorption qualities thereof to a markeddegree. Apparently the capillarity of the space between the adjacentfibres is reduced by the inclusion of fibres having certainwater-repellent properties, which is inherent in certain crude,untreated libres.

I have discovered that the above effects I have found, for

tion material, as finely comminuted sponge.'

I have found also that by the use of sponge with plant fibres,particularly the Broussa- 'netz'a pop3/rifare, or fibres mainly ofBro/usi l eonetz' papyrz'fem, that a remarkable rapidity in recovery isattained. Moreover, the increase in capacity or, 1n other words, the

' amount of ink which the ribbon is able to rather than letters.

hold is greatly increased without `attaining the point at which blottingcommences, or, in other words, the point at which the amount of ink inthe ribbon is so great that it will fill the type, thereby producingblots It is apparent, therefore, that by the use-of lthis material whichI shall describe more in detail, thelife of the ribbon will be greatlyincreased due to its increased ink capacity, and furthermore, thefeeding qualities, or, the rate of recovery is greatly increased.

It is the primary object of my invention to provide a ribbon made fromplant fibres in which the feeding qualities and rate of recovery aregreatly increased over thatfof ribbons of this character heretoforeproduced.

Another object of the invention is to provide a typewriter ribbon mademainly from fibres of Broussonezfz'a papymfera and containing sponge toimprove the working qualities of the ribbon.

With these and other objects in view the invention comprises the variousfeatures hereinafter more particularly described and p defined in theclaims.1

The invention is illustrated in the accompanying drawings, in which;

Figure l is a view in perspective of a portion of a typewriter ribbon;

Figure 2 is a front view of a typewriter showing a ribbon therein; andlFigure 3 is a diagram indicating the process steps employed for themaking of the typewriter ribbon.

In the drawings the numeral l indicates a typewriter ribbon and thenumeral 2 indicates a typewriter in which the ribbon is used in theordinary manner.

The fibres of the Japanese mulberry, known as the Bro'ussonetmpapym'fcra., are particularly adapted for the making of typewriterribbons, by means of which the necessary tensile strength and resistanceis attained, and by which the cost of typewriter ribbons is greatlyreduced. I found that the ribbons could be made fromv the fibrescomposed mainly of the Broussonetz'a papym'fem but having a smallproportion of other fibres admixed thereto, without substantialinterference with the qualities required in a serviceable ribbon. Asabove set forth, however, it has been found that certain fibres,particularly in their crude state, such as jute, interfere, if used insufficient amounts, with the feeding qualities of the ribbon, eventhough not added in sufficientamounts to decrease the tensile strengthand resistance to pounding to the point where the ribbon would beunsatisfactory as `to these properties. If sponge material, which hasbeen very finely comminuted, is added to the fibres of the Broussonetz'papy/Micra or to a mixture of these fibres with other fibres in thebeater, it is found'that the sponge becomes very thoroughly disseminatedamong the Broussonetia7 libres and although it does not add to thetensile strength of the ribbon it increases the feeding qualitiesthereof. A satisfactory ribbon may be made with a mixture of fibres inwhich the Broussonetia fibre is used in sufficient amount to give theribbon the required strength, kand a sufficient amount of sponge isadded to raise y thefeeding qualities or the recovering properties aconsiderable amount, whereby the addition of jute, and other fibreswhich would ordinarily reduce the feed or recovery, may be made withoutdetriment.

The proportions which I preferably use in my new ribbon are about Z5 percent of the fibres of the Broussomta papym'fem and 25 per cent of spongematerial, although I do not confine myself to these limits. In place ofthe above proportions I might employ only 10 per cent of the spongematerial with per cent of Broussonetia fibres. An example of theproportions which ma be used with a mixture of fibres in whichBroussonetiaf7 fibres are employed f to impart the required tensilestrength to the ribbon, is the following: a proximately 60 per cent ofthe Broussonetiai fibres, 20 per cent of hemp fibre, and 20 per cent ofcomminuted sponge.

In making up the mix it is preferable to first comminute the spongematerial, and then add it to the fibres in the beater. It has been foundthat the sponge cannot be comminuted sufficiently by the use of theordinary beater, in which the material is cut by rotating knivesB By theuse of a beater operating on a somewhat different principle from theordinary beater7 that of ammering the sponge material, it may beeomminuted to a point where the various particles of sponge readilyinterlace, thus acquiring a high degree of adherence to other fibres andeven to other shreds or bits of sponge material. After the sponge issufficiently comminuted it is added to the other bres inthe ordinarybeater, and thoroughly mixed, the rocess being finished in the usualway. y incorporating sponge particles of this character with fibres ofBrouesmz-etz'a papyrz'fef/'a or mixtures thereof with other plantfibres, a very high tensile strength is attained and the feedingpropersponge material which comprises' tubes or formly during use ofthe'ribbon.

hollow fibres, which act like springs, giving resiliency to the ribbon,and apparently, because of this property, increasing the wear under thetype. The sponge material serves also to increase the ink ca acity of aribbon or, in other words, ena les the ribbon to soak up a large amountof ink and give it ofi' gradually and quite uni- It is to be understoodthat I have described the preferred method of carrying out my inventionbut that Various changesv may be made thereinwithout departing from thespirit or scope of the invention as'defined in the claims.

kHaving thus described the invention what is claimed as new is:

1. .A typewriter ribbon comprising felted plant fibres and ink,` and amaterial to increase the ink feeding or recovery propertie-s thereof. 'v

2. A typewriter ribbon comprising plant fibres and sponge with inkingmaterial.

3. A typewriter ribbon comprising mainly fibres of the Broussonetia:papyrifera and sponge.

4. A typewriter ribbon comprising more than 50 per cent of plant fibresand commiiliuted sponge together with inking matena 5. A new article ofmanufacture adapted for typewriter ribbons which comprises a mixture ofcomminuted sponge, fibres of Broussoneta papywlfera andA other plantfibres in which the proportion of Broussonetia fibres is at leastone-half of the mixture, together with inking material.

6. A process of making typewriter ribbons which comprises pounding orhammering sponge material so as to suiciently comminute the material toadmix with plant fibres, thereafter mixing plant fibres therewith,forming the mixture produced thereby into a thin sheet of proper widthand thickness to be adapted for typewriter ribbons, l

and inking the said sheet.

7 A process of making typewriter ribbons which comprises comminutingsponge by hammering Athe sponge until the particles thereof arecomminuted sufficiently to la'dmix and adhere toV plant fibres whenadded thereto, mixing with the sponge particles thus comminuted plantfibres comprising mainly Broussonetz'a. papg/rz'fcm, thereafter mixingthe fibres and sponge in a beater until a homogeneous mixture isattained, forming thereafter from the mixture a thin sheet suitableorthe making of typewriter ribbons and adding inking material thereto.

8.A typewriter ribbon comprising substantially 60 per cent ofBroussonetia fibres, 20' per cent of hemp fibres, 20 per cent ofcomminuted sponge, and a suitable amount of inking material.

Signed at New York, N. Y., this 11th day of December, 1924.

CHARLES CAMPBELL.

